Lighting fixture



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- LIGHTING FIXTURE Filed NOV. 9, 1940 'lnvemorsz 1 Charles T. Mayterson, 1

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Patented Apr. 21, 1942 LIGHTING FIXTURE Charles T. Masterson, East Cleveland, and Wentworth M. Potter, Lyndhurst, Ohio, assignors to General Electric Company, a corporation of New York Application November 9, 1940, Serial No. 364,98;

(Cl. 240-48)v 4 Claims.

The present invention relates to lighting equipment generally and more particularly to equipment for the general illumination of interiors.

An object of the invention is to provide an attractive and unobtrusive lighting fixture for linear light sources, such as elongated, tubular fluorescent lamps, which conceals the lamps from view at ordinary angles of observation, serves as a secondary light source of lower surface brightness than the lamps concealed thereby and makes available for illuminating purposes outside the fixture and in the interior space to be illuminated most of the light emitted by thelamp. Another object of the invention is to provide a softly luminous fixture giving an impression of inappreciable weight to the observer. A further object of the invention is to provide a louver for such lighting fixtures which is separable to facilitate transportation thereof, easily assembled into a rigid body and demountably secured to other elements of said fixture to facilitate lamp renewal and cleaning of the fixture. Further objects and'advantages of the invention will appear from the following detailed description of an embodiment thereof.

The new lighting equipment comprises a refiector, a louver member demountably secured to the reflector and a linear light source, such as an elongated, tubular fluorescent lamp, mounted between said louver member and said reflector. The louver member of the present invention is made up of a'plurality of thin, elongated, spaced, parallel elements mounted in vertical planes transverse to the longitudinal axis of the tubular lamp and a plurality of similar members mounted in vertical planes parallel to, said lamp. Said transverse and parallel members intersect and interlock to form a rigid louver of substantial depth shielding the lamp from view at ordinary angles of observation and providing a plurality of apertures for the passage of the light from the lamp down to the surface or object to be illuminated. The louver also comprises light diffus- Fig- 2 is a plan view of an embodiment of the I invention and Fig. 3 is a fragmentary, elevational,

ing, translucent elements interposed between the eye of the observer and the lamp at the usual angles of observation which are, in effect, secondary li ht sources of lower surface brightness than the lamp and which appear as luminous elements to give an aspect of inappreciable weight to the fixture as a whole.

The invention will be readily understood from the accompanying drawing and the following detailed description thereof.

. In the drawing Fig. 1 is a side elevational,

partly sectional view along the line l-l of Fig. 2;

partly sectional view along the line 33 of Fig. 2.

Referring to Figs. 1 to 3, the lighting unit comprises a reflector housingl having sides of equal length which is supported by the ceiling of the, interior space to be illuminated. When desired, the sides of housing I are unequal in length. Said reflector housing I is of sufflcient depth to accommodate the wiring and the auxiliary apparatus (not shown for simplicity of illustration) for the elongated, tubular fluorescent lamps 2 and the base part of the sockets 3 supporting the lamps 2. When desired, the auxiliary apparatus is mounted in the ceiling. The outside diameter of the lamps 2 is one and onehalf inches. The part of the sockets 3 accommodating the bases of the lamps 2 project into the space between the reflector-housing l and the louver member 5 and support the lamps 2 in equally spaced, parallel positions with their longitudinal axes in a common plane parallel tothe planar -reflecting surface of reflector-housing I. The edge portions 4 of said housing I slope upward and outward for directing part of the light from the lamps 2 toward and along the ceiling. When desired, the central portion of the housing I consists of or comprises a reflector of specular control, such as a parabolic or .an elliptical refiector.

The louver member 5 has sides parallel to those of housing I and is supported against the lamps 2 by the springs l4 attached to the housing I. Saidmember 5 comprises a plurality of flat elongated strips H), II and I2 having rounded ends. Said strips I0 and H are mounted in vertical, equally spaced, parallel planes between the lamps 2 and extend parallel to the longitudinal axes of the said lamps 2. The strips Ill, and II are two and three-quarter inches in depth. Strips l2, which are two and one-half inches in depth, are mounted in similar planes transverse to the axes of the lamps 2. The outwardly rounded ends of all the strips are arcs of a circle having a radius of one and-one-quarter inches and its center in the median line of the strip. Said "strips l2 in-g by operating machinery or the like. The strips II have vertical slots about five and one-half inches apart extending from the top edge toward the bottom edge thereof. The transverse strips I2, at the parts engaging with strips II, have vertical slots separated the same distance extending from the bottom edge toward the top edge thereof, and similar slots extending from the top edge toward the bottom thereof at the part engaging with the strips III. Said strips I have slots therein extending from the bottom edge toward the top edge thereof for engagement with the strips I2. The slots in all of said strips III, II and I2 have straight sides and make a mechanically tight, frictional joint with the portion of the strip inserted therein so that the louver member 5 is a rigid body when assembled. The bottom edges of all said strips are in the same plane.

The louver member 5 also comprises slotted, curved end pieces I6, II, I8 and I9 which are supported by the strips III, II and I2 which are also slotted to accommodate and support said end pieces, as shown. Said end pieces I6 and I! extend longitudinally of the lamps 2 and the end pieces I8 and I9 are transverse to said lamps 2. All of said end pieces are elongated, curved strips attached to each other at their extremities by metal holding strips 20. In cross-section the end pieces are sixty degree arcs of a circle having a radius of approximately five inches and its center located approximately one inch below the bottom edge of strips III, II and I2 so that said end pieces slope upward and outward, as shown. The top edges of the pieces I6, II, I8 and I9 are in a horizontal plane located above the top edges of the strips III, II and I2. The bottom edges of the end pieces are in the same plane as the bottom edges of the strips III, II and I2 and are five and one-half inches from the adjacent strips III, II and I2. The pieces I6, I1, I8 and I! and the sloping portions 4 of housing I distribute some of the light from the lamps 2 over the ceiling in both transverse and longitudinal directions from the lamps 2 to avoid a tunnel-like impression in the interior space illuminated. Some of the light from the lamps; 2 passes directly to the ceiling through the space between the refiector portions 4 and the end pieces.

The louver 5 conceals the lamps 2 from longitudinal and lateral observation from the usual angles of view. In the embodiment of the inventhe lamps 2 to reduce the brightness of the apparent light source without absorbing" an appreciable part of the light striking the surface thereof. The strips III, II and I2 are preferably approximately one-sixteenth of an inch thick and the curved, end pieces I6, I'I, I8 and I9,are one thirty-second of an inch thick. The curved shape of the end pieces is desirable for increasing the stiffness thereof to avoid deformation of these thin, translucent elements. The upper edge portions of the strips I0 and II extend above the corresponding edges of the strips I2 and between the lamps 2. These portions slope downward toward the rounded ends of said strips I0 and I I, as shown in Fig. 3, and provide complete shielding of the top of the lamps 2 from lateral observation while retaining a minimum depth of the strips I0 and II below the lamps 2. When desired, thestrips II), II, I2, I6, II, I8 and I8 consist of light-diffusing, translucent glass, or when desired the strips III, H and I2 consist of light-colored, opaque metal, such as aluminum, and the curved strips I8, II, I8 and I9 of a lightdiifusing, translucent plastic or glass. The end pieces I6, II, I8 and I9 consisting of light colored,

diffusing, translucent material transmit an appiece adjacent to the lamp. The louver 5 completely shields the lamp from longitudinal ob-' servation through an angle of 25 measured from a horizontal plane to a plane including the bottom edge of a strip or end piece and the top edge of an adjacent strip. For convenience these are called the shielding angles and are varied, when desired. For example, both of these shielding angles are 40 angles or the lateralshielding angle is 50 and the longitudinal shielding angle is 32, when desired. The top portion of the pieces I6, I1, I8 and I9 shields the top portions of the lamps 2.

Laminated plastic material, such as Textolite," is preferred for the strips III, II, I2 and the end pieces IS, IT, I8 and I9. in weight and color and diffuses the light from This material is light preciable part of the light incident on the surface thereof and appear as elongated, luminous elements of comparatively low surface brightness to give an aspect of inappreciable weight to the fixture in spite of its relatively large size. This is highly desirable in the illumination of interiors where the presence of large, .heavy, opaque, massive-looking lighting fixtures suspended from th ceiling has a depressing effect on the observer. The impression of lack of weight of the unit is enhanced when the strips III, II and I2 also consist of light-diffusing, translucent, light-colored material. Lighting fixtures consisting of the preferred materials and having the dimensions and the arrangement of parts specified heretofore make available for illuminating purposes outside of the fixture approximately 72.6 per cent of the total light output of the lamps, 2. Fixtures embodying the invention are thus highly efficient units for general illumination.

The structure of the sockets 3 illustrated is described in the United States Reissue Patent No. 21,545, issued August 27, 1940 and assigned to the assignee' of the present application. Other types tion of interiors.

and the other advantages of the invention. Rigid means for supporting the louver 5 from the hous- I ing I are used, when desired, and the support means is attached to other parts of the louver, when desired. The edges of strips I6, I1, I8 and I9 are strengthened by metal strip supports, when desired. Any suitable means, such as bolts or rods fastened to the reflector l and supports in or on the ceiling, are used to support the fixture.

From the foregoing it is apparent that the new fighting equipment combines the advantages of shielding the light source from the eye, allowing most of the light from the lamps to be available for illuminating purposes and to come directly down to the surface or object to be illuminated,

distributing some of the light on the ceiling to avoid unpleasant contrasts and a tunnel-like impression, being softly luminous to blend with its luminous background and to appear at inappreciable weight, and being easily assembled and separable for transportation, lamp renewal and cleaning purposes.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A separable louver for concealing a linear light source from observation, said louver comprising a plurality of intersecting, inter ocking,

' spaced strips of substantial depth forming a plubetween said source and the eye of an observer at ordinary angles of observation.

2. A separable louver for concealing a linear light source from observation, said louver comprising a plurality of strips straight; in transverse section which intersect each other in a multiplicity of straight, parallel lines and a plurality of strips curved in transverse section which intersect said first-named strips in a multiplicity of curved lines.

3. A separable, rectangular louver for concealing from observation a row of parallel spaced, elongated lamps, having their longitudinal axes in a common plane, said louver comprising a plurality of intersecting strips straight in transverse sectionwhich intersect each other in a multiplicity of straight, parallel lines and which are disposed in planes normal to the plane-of said lamp axes and a plurality of strips curved in transverse section which intersect said firstnamed strips in a multiplicity of curved lines, said curved strips being the outermost strips of said louver.

4. A separable louver for concealing from observation a row of parallel, spaced, elongated lamps having their longitudinal axes in a common plane, said louver comprising a plurality of intersecting strips straight in transverse section which intersect each other in a multiplicity of straight, parallel lines and which are disposed in planes normal to the plane of said lamp axes,

some of said strips being parallel to and intermediate said lampswith an edge portion'thereof interposed between said lamps, and a plurality of strips curved in transverse section which intersect said first-named strips in a multiplicity of curved lines. 1

CHARLES T. MASTERSON. WEN'I'WORTH M. POTTER. 

